Dams, infrastructure require long-term maintenance

Monday, February 13, 2017

California officials have their fingers crossed as they keep an eye on the nation's highest dam, where erosion damaged one spillway and threatened to wash out an emergency spillway, sending a 30-foot wall of water toward the homes of at least 188,000 people.

Outflows were running 100,000 cubic feet per second from Lake Oroville, and inflows were just under 45,000 at last check.

Evacuations were ordered Sunday when officials feared the dam was as close as an hour to collapsing.

Officials had plenty of warning. The Sierra Club and two other groups filed a motion in 2005 as part of the dam's relicensing process to require the emergency spillway to be armored with concrete.

In their filing, they said the dam, finished in 1968 and owned by the state of California, would do just it did -- overwhelm the main concrete spillway, flow down the emergency spillway and cause erosion that could lead to failure.

Federal officials rejected the filing, however, saying the emergency spillway was designed to handle 350,000 cubic feet per second.

Sunday, the spillway began to erode when the flow reached a peak of 12,600 feet per second.

Dams are an important part of Nebraska -- "the flatwater state" -- where water is a precious commodity to be stored for irrigation and recreation, and where, like California, it can quickly appear in overabundance after a time of drought.

Most dams are showing their age, having been constructed in the middle of the last century.

The Red Willow Dam, which creates Hugh Butler Lake north of McCook, was just one example.

After a dry sinkhole was discovered in the face of the dam in 2009, the lake had to be drawn down and more than $15 million in repairs were completed by the end of 2011.

One of the major accomplishments of Gazette founder Harry Strunk and other civic leaders of the 1930s and 1940s was the construction of dams to prevent another devastating flood like the one that occurred on the Republican River in 1935.

However, dams, like highways, water, sewer and other major public infrastructure undertakings, require ongoing maintenance over their lifetimes.

From the planning stages through the lifetime of the structures, allowances must be made to ensure funding is available to make sure they are still safe.